Merseyside Police are appealing for CCTV and camera phone footage of an incident outside Anfield football stadium that left Irishman Sean Cox in a critical condition in hospital.
Two Italian men have been charged and remain in custody over the alleged assault - which happened shortly before Liverpool's Champions League semi final against AS Roma on April 24th.
Mr Cox, who had travelled to Merseyside for the match, has undergone surgery in the weeks since and remains in a critical condition in hospital.
This morning, investigators appealed to members of the public to come forward with any information relating to the incident - especially CCTV or mobile footage.
They are particularly interested in anything that may help identify a third man suspected of being involved in the assault.
Detective Inspector Paul Speight said officers' thoughts are very much with Mr Cox's family "who are going through an extremely tough time, and we want to bring anyone responsible to justice.
"We have studied CCTV footage and have spoken to a number of witnesses, and I want to thank the people who have already come forward for their ongoing support," he said.
"We know there were a number of people filming on camera phones before and after the incident, and we are very keen to hear from them and view the footage, as it could prove vital to our investigation of this incident."
Anyone who was filming or has access to CCTV footage in the area around Anfield between 7pm and 7.45pm is asked to send the footage to Anfield.Incident@merseyside.pnn.police.uk.
You can also contact police directly through Twitter, Facebook or by phone.
Earlier this week, Mr Cox's family said they have been "overwhelmed and humbled" by the support they have received from all over the world over the past two weeks.
"There are no words to describe the gratitude we feel to the ordinary people of Liverpool and Ireland who have taken Sean to their hearts in a way that underlines why those places have such a deserved reputation for generosity and solidarity," they said in a statement.
"Every day letters and cards arrive from this country, from Ireland and beyond.
"Every one of them wishes us well and the accompanying offers of support have reminded us, even in our darkest moments, that we are not walking alone."